Radio loud speaker



March 12, 1929. J KERSTEN 1,704,976

RADIO LOUD SPEAKER Filed May 15, 1926 2 Sheets-Sheet l liggi vmwz I flflmmu March 12, 1929. J. KERSTEN 1,704,976

RADIO LOUD SPEAKER Filed May 15, 1926 2 Sheets-Sheet 2 B Jacob Kevan Patented Mar. 12, 1929.

UNITED STATES PATENT OFFICE.

JACOB KERSTEN, OF ALLEGAN, MICHIGAN.

RADIO LOUD SPEAKER.

Application filed ma 15,

This invention relates to a sound amplifyil'lg construction designed to be used in connection with a radio loud speaker unit. It. is an object and purpose oi? the present. invei ion to make a device. of this character in a simple and economical mannerand one which will be attractive in appearance and with which blasting of sound at certain pitches thereof is completely obviated. The invention consists of novel constructions and arrangements of parts which will be fully understood from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a front elevation of the sound amplifier.

Fig. 2 is an enlarged vertical section through the outer housing or shell of the structinro shown in Fig. 1, substantially on the plane of line 22 of Fig. 1, the amplitying horn within said shell being shown in side elevation except for the lower end which is in section.

Fig. 8 is a horizontal section on the plane of line 3 3 of Fig. 4,

Fig. 1 is a front elevation of the amplifying horn which is located within the enclosing housing, and

Fig. 5 is a fragmentary vertical section through the lower part of the horn, housing and base, in a plane at right angles to Fig. 2.

Like reterenco characters refer to like parts in the different figures ot the drawing.

In the construction of the sound amplifying apparatus an outer housing is used which includes two conical parts, the back 1 and the front 2. These parts are preterably formed of paper but the type of material, used is not controlling in any respect and the same may be pressed from bakelite or otherwise made. The back 1 and the front 2 at their edges where they are placed together have annular projecting lips 8 which when the two parts of the housing are brought together he against each other. The front 2 is provided wit-h a plurality of openings 4 which may be of any suitable design and on the inner side of said front 2 an open mesh fabric 5 is secured. The two parts of the housing are held together by an annular clamping ring 6 preferably of sheet metal which has a groove at its inner side to receive the lips 3 and is securel clamped thereagainst.

The amplifying horn is located within 1926. Serial No. 109,211.

said. housing. The horn comprises a downwardly extendingneck 7 which. extends be low the lower side of the housing for a short distance, and a body which lies wholly within the hon. g The body of the horn connect with the upper end of the neck, progressively enlarging as it extends upwardly and. to one side from said neck, as indicated at 7, thence curving upwardly and laterally and. then back in the opposite direction, and having a front side 8 terminating a short distance to one side of a vertical plane passing through. the axis of the neck 7. The back side 10 of the body is extended farther and curved downviuidly, as shown, and to a side of the portion 7 a section 11 integral with the back 10 is lo cated terminating in the forwardly and latorally c irved lip 12. For reinforcement purposes a web 9 of paper or other suitable material cemented between said lip 12- and the adjacent portion 7 of the horn.

This horn, thus made, extends upwardly and to one side from the neck 7, then curved in the opposite direction to the other side, the front terminating short of the termination of the back 10 so that a .relatively wide frontopeniug for the escape of sound waves is made.

hen the horn is placed within the housing it substantially iills the same, the back 10 thereof coming against the inner side of the back 1 of the housing while parts of the front side of the horn come against the inner side of the front oi the housing between the openings l: and are cemented. thereto. flhis makes a very firm structure and one incapable of excess vibration in so far as possibility of blasting is concerned, yet acts in a measure as a sounding board to amplify, modulate and control the sound emitted.

The combined horn and housing therefor is supported on a pedestal 13 which is formed with an enlarged recess 14: at its lower side with a vertical opening 15 extending upwardly througl'i the pedestal from the recess into which the neck 7 of the horn extends, the lower edges of the housing being received in a seat formed in the upper side of the pedestal. A loud speaker unit 16 adapted to be located in the recess 14 from which a tube 17 extends upwardly into the lower end of the neck 7. A plate 18 connected with the tube 17 is permanently lot) secured by screws or other fastenings to the pedestal and holds the loud speaker unit in place.

In Fig. 5 a different form of the construction, in so far as the lower-end of the horn and its manner of attachment to the pedestal is concerned, shown and this form is one which, for several reasons, is preferred. The pedestal 19 is a hollow casting ofmetal, preferably aluminum for lightness, across which at lower portion a cross bar 20 extends having an opening through which an upper threaded outlet 21 to the loud s )eaker unit 16 projects, threading into the lower end of the neck 22 of the horn which, in this case, of metal, preferably aluminum, and is formed with an annular shoulder 22 which bears against the upper side of the cross bar 20 around the opening therethrough. The upper end of the neck portion 22 is bent laterally as indicated at 23 and joins with the gradually enlarging section 7 of the horn. Otherwise the horn is of the identical construction shown in Fig. 4.

The pedestal 19 is of greater height than that shown at 13 so that the neck 22 is of greater length than the neck 7, this providing a longer column of air into which the sound waves are directed. The assembly is very simple requiring only the positioning of the lower end of the neck 22 through the opening of the bar 20 and the attachment of the loud speaker unit by screwing projection 20 into the lower end of said neck, this serving to bind the parts securely together.

This invention of loud speaker unit has been perfected after long experiment and trial and has proved especially practical and useful. The sound passing from the mouth of the horn is directed outward through the openings 4 in front of said mouth. The extension to the back side 10 of the horn be yond the front side with its dished formation. is a feature of the construction which is very desirable and necessary for the attainment of the best results. It directs the sound forwardly and by reason of its secure attachment to the back of the outer enclos ing housing, makes a substantial sound board in which excess vibration does not occur while vibrating in'synchronism with the sound waves to properly reproduce and amplify the same. Uncontrolled and harmful vibrations are eliminated. The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

'1. An amplifying horn comprising a body and a neck extending downwardly from the body, said body of the horn being turned laterally and curved upwardly and over said no k and progressively enlarged as it extcndsnway from said neck, and having front its and rear sides, the rear side being extended beyond the front side and having concave form. i

2. An amplifying horn comprising, a neck of metal to the lower end of which a loud speaker unit is adapted to be attached, said. neck having its upper portion turned upwardly an d laterally at an angle to the vertical, and a body connected to the upper end of the neck and curving upwardly and laterally away therefrom and thence back over said neck, with the rear side of the body extended downwardly and outwardly beyond the front side thereof formed with a concaved shape. 7

In a construction of the class descrioed, a housing comprising two conical housing members having their base edges located againsteach other, means for securing said members together, the front member being formed with openings therethrough, and an amplifying horn located inthe-housing having a neck extending through the lower side of said housing and within the housing being turned laterally and upwardly and en larged progressively away from said neck, the front and rear sides of the horn flaring outwardly to engage against the inner sides of said frontv and rear members of the housing, and the rear side of the horn extending beyond; the front side thereof and formed into concave shape, substantially as described.

41;. A construction containing the elements in combination defined in claim 3, said rear side of the horn where it engages against the inner side of the rear member of the housing being cemented thereto, substan tially as and for the purposesdescribed.

5. An amplifying construction comprising a hollow housing, a horn located within said housing and having a neck extending through the lower side thereof, said horn being curved laterally and upwardly away from theupper end of the neck and enlarging progressively away from said neck and having front and rear sides bearing against the front and rear sides of the housing, the rear side of the'horn being extended beyond the front side and formed into concave shape, and said housing in front of the horn having openings for the escape of sound.

6. A construction containing the elements in combination defined in claim 5, combined with an open mesh fabric secured at the inner side of the front side of the housing and across the openings therein. u 7 '7. In a sound amplifier, a horn having a depending neck, said horn bending laterally .to one side from the upper end of said neck and curving upwardly and over said neck and enlarging progressively away therefrom, the front side ofthe horn terminating short of the rear side, which rear side is extended downwardly and beyond the front side and formed into concave shape and a member of conical form lying against and secured to the rear side of said horn, substantially as described.

8. In. a sound amplifier, a housing comprising a conical back member and a conical 'l'iront IHGII'llJGF located against each other and swured together at their edges, said t'ron t member having openings therethrough and a horn substantially filling said housing' and hearing against the inner sides of the front and bark members and having a neck extending); through the lower side of the housing.

9. kn pend i n y;

am )lit in;;' horn comprising a devertical neck and a horn structure extending laterally and upwardly away from said neck, said horn structure enlarging progressively in a direction away from the upper end of the neck, and having a rear side extended beyond and downwardly from the terminal edge of the front side and formed into concave shape, said depending portion of the back having an inner edge spaced. a short distance from the adjacent inner side of the horn, and means extending; l. etwe-en and connected to said inner edge of the depending portion of said back and the adjacent portion of the horn substantially as described.

In testimony whereof I afiix my signature.

JACOB KERSTEN. 

